This invention generally relates to protection of data supports against falsification and duplication, particularly to a method of characterizing and identifying falsification-proof data supports, such as value or identity cards, in which physical characterizing features of the data support are measured and converted into characterizing data which are recorded on the data support, as well as a device for performing the method, and a data support which is suitable therefor. The invention also relates to a data support suitable for performing the method, and to an identification device for using the data support in view of performing the method.
Conventional automatically readable authorization cards or value cards are inserted into machines for distribution of wares or services, or identification of the person who is the owner of the respective card. For example, authorization cards may be used to allow access to an area or building. Value cards may be used as check cards to deliver money from an automatic money distributor. Examples of use of identity cards are automatically readable papers or passports.
With all kinds of use of those data supports it is important to avoid falsification or counterfeiting thereof, particularly also in cases where non-authorized persons get into possession of the primary data support material not yet provided with specific identification signs. Also, production of duplications by imitation of recorded data supports or cards must be rendered impossible to the falsifier.
In order to secure data supports, it is known to arrange a series of recording zones on the data support raw material and to record information therein. Upon use of the cards as data supports, this means that each non-recorded raw card contains a certain information in permanently recorded form, which information may e.g. be an identity number of the particular card. The card is further provided with a magnetic track for recording of a variable information. Recording of the magnetic track with the variable information is performed when the card is delivered to the authorized person. In case of an automatically readable check card, the variable information may e.g. be the account number of the owner, the date of delivery, the account status etc. In addition to the variable information, characterizing data are recorded on the magnetic track which correspond to the identification data of the respective raw or primary card. Upon each identification of the card in an automatic machine, the identification data of the raw card are detected and compared with characterizing data recorded on the magnetic track. The card is recognized as being authentic only in case of coincidence. This method has the advantage that non-authorized persons who are in possession of the raw card may not simply record some arbitrary data on such raw card in order that the machine may accept the card as being authentic. Rather, it is necessary that characterizing data are recorded on the magnetic track which correspond to the physical characterizing features of the respective raw card. As these characterizing features are different from one card to another, imitation of the cards is rendered difficult. However, the known method allows falsification by duplication, by providing the card raw material with the same physical characterizing features as those of an original card in possession of the falsifier. In this case, the information recorded on the magnetic track of the original card may be copied on the magnetic track of the falsified card without modification.
With the known cards considered as being falsification-proof, criteria of authenticity are symbols, markings, inside layers etc. applied on or within the card material. Further, it is possible to evaluate specific features of the card raw material which may be detected by measuring techniques, for example stampings, the thickness of layers, card size etc. All of these features may be detected by measuring techniques. They may be discovered and detected by falsifier. Because detectable markings are susceptible of analysing and analysed markings are susceptible of reproduction, the production of duplications is quite simple to a skilled falsifier, with the known methods.